Keithley 237

SECTION3
IEEE-488 Reference
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3.6.14 P- Filter
Purpose
Format
Parameters
Default
Description
Programming
Notes
Programming
Example
3-46
To control the number of readings averaged.
Pn
PO
P1
P2
P3
P4
PS
Filter disabled
2readings
4readings
8readings
16readings
32readings
Upon power-up, or after receiving a DCL or SOC command, the instrument defaults
to the last programmed selection. A JOX command sets the instrument to PO (filter
disabled).
The P command controls the amount of filtering for each measurement. With the fil-
ter enabled, the unit acquires and averages up to 32 successive A/D conversions for
each measurement. Since noise
is mostly random in nature, it can be largely canceled
out with this method. With the filter disabled, only one reading is taken.
1. Filtering only occurs on a measurement, not across measurements.
2. Filtering can have significant impact on measurement speed and allowable pulse
times.
3.
If a pulsed sweep is in the buffer, changing the filter selection causes the instru-
ment to recalculate the delay times to maintain the specified toN and toFF.
4. The conversions averaged are per the selected integration time.
10
OUTPUT 716; "P3X"
20
OUTPUT 716; ''POX"
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! Enable filter and set to eight
readings.
! Disable filter.